According to my DB the lowest price is $40.41 for HSKRC MAK5 225mm 3K Carbon Fiber 5 Inch RC Frame Kit (in Banggood). Just check coupons out (with price alert and history). Best price?
, Weight: 170g approxi. (include 3D Printing Parts), VTX Mounting Hole: 30.5×30.5mm / 20x20mm, Item Name: 225mm Wheelbase 5 Inch Frame Kit, Upper Plate Thickness: 2.5mm, Camera Mounting Hole: 19-20mm, Model: MAK5, Brand: HSKRC, Motor Mounting Hole: 16x16mm / 19x19mm, Inner Height: 25mm, Flight Controller Mounting Hole: 30.5×30.5mm, Wheelbase: 225mm, Material: 3K Carbon Fiber, Screw Size: M2 and M3, Bottom Plate Thickness: 2.5mm, Arm Plate Thickness: 5mm
Latest coupon and price update (UTC):
Banggood ($40.41)
Banggood warehouse is located in China. Too bad there’s no coupon right now in Banggood. Well, is it a good price anyway? Hmmm, price is higher than average (which is $36.85 right now), so better set price alert down below…
Link: Banggood product page
Price: $40.41
Exclusive Allowance Coupons: https://bit.ly/3xWgD9k and https://couponsfromchina.com/short/5cd
Old coupons (from the oldest to the newest): Cuponation9, BGMatt2022, BGGutscheine, BGToys8, BG8OFFCOUPON, TTBLACK5, BG589b2e, BG8FORMULAMX
(system checks these coupons on every price check (like once per 24 hours), but you can check them out anyway)
Aliexpress
There’re some similar (or not) items on Aliexpress
Click here to search by yourself. Here are coupons that you can use.
Price history and price alert
Check out price history chart (for all/most countries) for HSKRC MAK5 225mm 3K Carbon Fiber 5 Inch RC Frame Kit.
Price records source(s): Banggood
Click on image to enlarge. 
You can set price alert (for Banggood and Aliexpress (only if product name will be the same as on Banggood and I will post it on social media though, so it’s more like Banggood price alert)).